A. Field of the Invention
The present invention relates generally to toothbrushes, and, more particularly, to a toothbrush assembly having an environmentally safe polymer battery.
B. Description of the Related Art
Many conventional toothbrushes use batteries to power movable bristles and/or to illuminate light sources provided in the toothbrush handle. For example, various types of powered toothbrushes are generally known in the art. U.S. Pat. No. 5,625,916 discloses an electrically driven toothbrush having a motor drive for rotating a drive shaft. The drive shaft connects to a bristle holder on the head of the toothbrush in such a manner that rotation of the drive shaft causes the bristle holder to rotationally oscillate back and forth. Various other arrangements are known for oscillating a bristle holder mounted to the head of an electric toothbrush.
U.S. Pat. No. 5,416,942 shows a further type of powered toothbrush wherein the head includes a pair of concentrically arranged sections, each of which is driven in a rotationally oscillating manner in opposite directions.
U.S. Pat. No. 6,032,313 discloses a household appliance such as a toothbrush that may be used for cleaning, polishing, or massaging. The head of the appliance includes a plurality of co-axially rotatable or parallel linearly-movable sections, but fails to provide other bristle-containing sections.
U.S. Pat. No. 5,070,567 discloses an electrically-driven toothbrush that includes a rotatable brush head having bristles thereon. A further group of bristles, each of which rotates around its own axis, reside adjacent to the brush head.
Known illuminated toothbrush constructions include an enlarged handle housing circuitry connected to a battery for powering small light bulbs mounted in the handle wall to form a plurality of light points on the surface of the toothbrush. This is seen in U.S. Pat. Nos. 4,845,796 and 5,339,479. The purpose of such a construction is, at least partially, to motivate children to brush their teeth, as the pinpoints or discrete areas of light are deemed to add an element of interest and novelty to the brushing process, offering a fun and exciting way for children to brush their teeth. Such excitement motivates children to brush their teeth often, to set in place lifelong habits of good oral hygiene. Standard micro batteries may be used to provide sufficient power to illuminate the toothbrush during brushings for six to twelve months, which is about the normal useful life of a toothbrush. However, replacement batteries may also be used.
All of these toothbrush patents disclose use of conventional batteries. Unfortunately, conventional batteries (e.g., alkaline batteries) have their shortcomings. First, they are not physically or environmentally safe. Potassium hydroxide electrolyte, a strong alkali, is contained within the cells of the batteries. If alkaline batteries are damaged or mishandled, the potassium hydroxide may leak out of the battery cell. Severe chemical burns can result if potassium hydroxide comes into contact either skin or eyes. Conventional batteries account for a significant percentage of heavy metal contaminants in landfills and incinerators. The major concern with consumer batteries in landfills is their corrosiveness and toxic heavy metal content. As the batteries are damaged or corroded, the contents spill into the environment. Second, conventional batteries used for toothbrushes (e.g., AA batteries) are typically not small in size. Finally, conventional toothbrush batteries are not flexible, but rather contain rigid housings (e.g., housings of nine-volt batteries).
A promising application of conducting polymers is in energy storage devices. Battery systems have been extensively studied where a p-dopable conducting polymer is uses as the cathode active material and a metal, often lithium, is used as the anode active material. Various p-dopable materials have been studied: polyacetylene, poly-(p-phenylene), polypyrrole, polyaniline, etc. A battery with n-dopable conducting polymer, polyacetylene, as the anode material and a metal oxide as cathode active material has also been described. Such batteries may be constructed from multiple polymer films, making them lightweight and flexible. Since polymer batteries are moldable into various shapes and flexible, they may be incorporated into compact devices and take up much less space. These polymeric batteries have remarkably high charge capacities, and excellent cycling efficiency. The provision of polymeric materials further permits the polymeric battery to be substantially free of metal components, thereby improving handling of the battery and obviating the safety and environmental concerns associated with conventional batteries. Various types of polymer-based batteries are known in the art, as shown in U.S. Pat. Nos. 4,801,512, 4,804,594, 5,527,640, 5,665,490, 5,733,683, and 5,888,672.
Despite the desirable features of polymer batteries, none of toothbrush art discloses a toothbrush (manual or powered) that uses an environmentally safe polymer battery. Thus, there is a need in the art for a toothbrush that uses such a battery. Such polymer batteries contain no heavy metals making them environmentally safe; are low in cost; are small in size, saving space in the toothbrush housing and enabling the housing to be smaller (saving on materials of construction); can be shaped to fit into the housing design; and exhibit high charging capacities with excellent cycling efficiencies.